1. Field of the Invention
This invention relates to an inflation device and, in particular, to an inflation device for lifejackets and the like which is capable of both manual and automatic actuation. Such devices are known in the art as Autoinflators.
Various examples of autoinflator are known, one example being that shown in U.S. Pat. No. 5,601,124. This patent describes a device in which the automatic and manual actuators rely on different sets of components, with the result that there is a relatively large number of operating parts. This, in turn, influences cost and raises potential reliability issues.
2. Description of Related Art
GB 2 278 911 (Mackel) discloses an autoinflator in which a cammed arm is capable of driving a puncture pin into a gas cylinder. The arm is held in repose by a torsion spring around the pivot, but is connected to a lanyard at the end of the arm. Pulling the lanyard with sufficient force to overcome the torsion spring causes the arm to rotate and so drive the pin into the gas container.
The lanyard is also connected to a slidable member itself attached to a spring. The spring has a tendency to pull the slidable member, so operating the lanyard, but the slidable member is held in place by a retaining pin, transverse to the line of sliding. A soluble element holds the retaining pin in position, the soluble element being firmly held against the retaining pin by a resilient member. The dissolution of the soluble element causes the pin to disengage from the slidable member, and so causes the inflation of the device. If the lanyard is pulled with sufficient force it will overcome the retaining pin and cause inflation.
Though that apparatus requires fewer parts than autoinflators having distinct manual and water-activated mechanisms, it is still has many components capable of failure. The device may also be difficult to activate manually, since the retaining pin must be held firmly enough to disallow the tension spring to activate the device whilst the soluble member is still integral.
It is an object of this invention to provide an inflation device which has a lesser number of operating parts than typical prior art inflator devices or which will at least provide a useful choice.
Accordingly, the present invention provides for an inflation device for an inflatable article, said inflation device including:
a housing adapted to hold a container of pressurised fluid;
a displacement means including a piercing means displaceable so as to penetrate a container held by the housing and allow the release of said pressurised fluid;
actuation means having engaging co-operating elements which engage to retain the displacement means in an unactuated configuration, the actuation means releasing the displacement means both through the presence of water and by manual operation,
said co-operating elements being substantially radially arranged, one of the co-operating elements is capable of movement in a substantially radially outward direction, said actuation mew being operable to prevent the co-operating element""s movement, and one of the co-operating elements is capable of movement in a substantially radially inward direction, said actuation means being operable to prevent that co-operating element""s movement each co-operating element being the operable and movable separately to and independently of the other. Preferably the line along which the displacement means acts is coaxial with the radii of the co-operating elements.
Preferably the manually operable release means includes a plug which, in the unactuated configuration, prevents movement of the co-operating sections.
Preferably the water actuable release maw include a water sensitive sleeve which, in the unactuated configuration, surrounds and restrains the co-operating sections against movement but which, when immersed in water, degrades ad permits movement.
According to another aspect of the present invention there is provided an inflation device for an inflatable article, said inflation device including:
a housing for holding a container of pressurised fluid;
a displacement means including a piercing means displaceable so as to penetrate the container and allow the release of said pressurised fluid;
actuation means having engaging co-operating elements which engage to retain the displacement means in an unactuated configuration, the actuation means releasing the displacement means both through the presence of water by it water-sensitive control element, and through manual operation by a manual control element,
the actuation means including a retaining element having two retaining surfaces at an angle to each other, one surface bearing against the water-sensitive control element and the other against the manual control element, whereby an release of either control element, the retaining element slides put the other control element.
In the preferred embodiment described herein, the water actuable release means comprises a water sensitive sleeve which, in the cocked configuration, surrounds and restrains the co-operating sections against radially outward movement but which, when immersed in water, degrades and permits radially outward movement. The manually operable release means includes a plug which, in the cocked configuration, prevents radially inward movement of the co-operating sections. Manual removal of the plug permits inward movement and to release of the displacement spring.
It will be seen that since the coiled spring directly urges the piercing means forward, a linkage to convert the direction of the displacement means, such as the cammed arm in Mackel, is unnecessary. Because of this, and the coaxial arrangement of the components, fewer parts are needed, making the device less expensive to produce, and more compact and reliable.
That the force which disengages the co-operating elements is transverse to the force exerted by the restrained displacement means, whether activated manually or by the presence of water, allows, say, a large force (which may be necessary in order to pierce the pressurised container) to be initiated by a relatively small force applied manually. The force to activate the mechanism, and the force to pierce the container may be set independently to the optimum magnitudes.
Many variations in the way the present invention might be performed will present themselves to those skilled in the art. The description which follows is intended only as an illustration and the absence of description of particular alternatives or variants should in no way be applied to limit the scope of the invention. Such description of specific, elements which follows should also be interpreted as including equivalents whether existing now or in the future. The scope of the invention should be determined solely by the appended claims.